1. Field of the Invention
The invention concerns a supply unit for a movable gantry of an image acquisition device, particularly a medical image acquisition device. The supply unit serves to transport power and/or data and/or coolant between the movable gantry and a stationary connection point (generally designated as a supply source in the following).
2. Description of the Prior Art
In the following, a movable gantry (“sliding gantry”) means a structural unit that has at least one approximately annular housing (gantry) that is in penetrated by a tunnel, as well as components accommodated in the housing that enable an image acquisition. The entire gantry housing is movable, such as on rails recessed into the floor. For image acquisition purposes, the gantry is moved with respect to a patient bed associated with the gantry such that the bed is caused to protrude into the tunnel.
Such sliding gantries are presently used primarily in (x-ray) computed tomography systems (CT systems). An essentially annular mount (also designated as a ring collar) is supported inside the housing, on which mount are attached an x-ray source and a radially opposite x-ray detector. This mount rotates around the tunnel in a known manner to acquire slice images (tomograms) of a patient on the patient bed.
In a typical image acquisition method, projection images of a subject to be imaged (thus of the patient on the patient bed) are acquired slice-by-slice in a typical image acquisition method during successive feed of the gantry along the tunnel axis, and the projection images are electronically stored as image data. Finally, slice images or three-dimensional volume data sets of the subject to be imaged are calculated at a control and evaluation computer (associated with the gantry) by numerical back-projection of the acquired projection images. The acquisition of a series of projection images is also designated as a “scan” in the following.
Such a sliding gantry is frequently used in connection with an operation on the patient when an image acquisition is to take place in the course of the operation, and when a dedicated CT table cannot be used.
To operate the CT system, it is necessary to supply the sliding gantry with power and to transfer data (in particular image data acquired in a scan) as well as control signals between the gantry and the control and evaluation computer. In a liquid-cooled CT system, it is also necessary for a liquid coolant to be supplied to the gantry and discharged from it again.
In a conventional design, all conduits (for power, data and/or coolant) are directed from the gantry via a cable column into a component known as a ceiling module. The ceiling module is an (oblong) housing arranged near the ceiling (of an operating room, for example). This housing is arranged approximately parallel to the travel direction of the gantry. In the following, a device designated as a “power routing chain” is accommodated inside the housing.
Such a known power routing chain is a flexible module that directs and protects a conduit accommodated therein, and the power routing chain establishes a connection between the stationary supply source an a connection point with the gantry, whose location varies.